1. Field of the Invention
The present invention relates to a large, or an extra large multi-piece rim type disk wheel mounted to off-road vehicles, for example, construction vehicles, and a method for producing the same.
2. Description of Related Art
As illustrated in FIG. 6, the conventional multi-piece rim type disk wheel includes a rim base 1, a bead seat band 2, a lock ring 3, and a flange 4. In order to make the manufacture of a large-sized rim easy. The rim base 1 is usually divided into a gutter band la located at one end of the rim base 1, a back flange 1d located at another end of the rim base 1, and center bands 1b and 1c located between the gutter band 1a and the back flange 1d. The gutter band 1a, the back flange 1d, and the center bands 1b and 1c are manufactured separately and then welded to each other into the rim base 1.
Then, an outside portion 8a of a disk 8 having a T-shaped cross-section is fit to an inside surface of the center band 1c located in the center of the rim base, and the center band 1c and the outside portion 8a of the disk 8 are connected by a fillet weld.
When a construction vehicle needs to handle an increased movable load, which requires an increase in an axle shaft strength and a hub strength, outside diameters of the axle shaft and the hub need to be increased in order to meet the increased demand on the construction vehicle.
However, if the outside diameter of the hub of a conventional structure of a multi-piece rim type disk wheel were increased, the conventional multi-piece rim type disk wheel would interfere with a wheel coupling portion 9a of a hub 9 and a break drum 98b, as shown by a broken line in FIG. 2 (in which the conventional multi-piece rim type disk wheel is shown by the broken line and the structure of the present invention is shown by a solid line), so that it would be impossible to meet the needs of an increased movable load.